Possibility to run create() sequentially

[dciccale]

as @vkarpov15 commented here #723 (comment) the create() method runs a bunch of save() calls in parallel.

It would be useful to implement some kind of callback or sequential promises to allow keeping the order for example in a number sequence like in the following example:

OrderSchema.pre('save', function (next) {
  if (!this.isNew) {
    return next();
  }

  CounterModel.findOneAndUpdate({_id: 'orders'}, {$inc: {n: 1}}, {'new': true, upsert: true}, (err, doc) => {
    if (err) {
      next(err);
    } else {
      this.reference = doc.n;
      next();
    }
  });
});

Output:

[ { reference: '13' },
  { reference: '21' },
  { reference: '16' },
  { reference: '5' },
  { reference: '9' },
  { reference: '19' },
  { reference: '2' },
  { reference: '10' },
  { reference: '11' },
  { reference: '20' },
  { reference: '8' },
  { reference: '18' },
  { reference: '3' },
  { reference: '15' },
  { reference: '7' },
  { reference: '14' },
  { reference: '4' },
  { reference: '17' },
  { reference: '22' },
  { reference: '6' },
  { reference: '1' },
  { reference: '12' } ]

My current use case, is when a user imports a file into my app, for creating a bunch of documents, the reference number goes crazy, and I would expect them to keep the order.

I know this could be easily implemented by iterating myself and running save() however It could be an option in the create() method and probably more performant 👍

[velichkov]

👍

[vkarpov15]

As a workaround you can do async.series() or just .save() in a for loop if you're using co